直线超声电机驱动的平面3-PRR并联平台的运动学标定  

Kinematic Calibration of a 3-PRR Planar Parallel Manipulator Driven by Linear Ultrasonic Motors

作　　者：周丽平[1] 张泉[1] 孙志峻[1] 

机构地区：[1]南京航空航天大学机械结构力学及控制国家重点实验室,江苏南京210016

出　　处：《机器人》2014年第4期485-490,共6页Robot

基　　金：国家自然科学基金资助项目(51175264;51275235);2009年度NSFC-广东联合基金重点项目(U0934004);中央高校基本科研业务费专项资金资助项目(NS2012033;NJ20130004)

摘　　要：以直线超声电机驱动的平面3-PRR并联平台为研究对象,基于视觉测量对它进行了运动学标定.首先介绍了该并联平台结构,然后推导了其运动学模型并给出了误差函数指标.针对并联平台运动学标定问题,利用CCD相机作为外部测量装置,通过图像处理技术对动平台上的人工特征中心定位,实现了对并联平台动平台位姿的精确测量;最后利用粒子群算法对并联平台运动学参数进行了优化,实现了对并联平台的运动学标定.标定实验结果表明:动平台走一个长轴为16mm、短轴为10mm的椭圆形轨迹,标定前轨迹误差最大大于800μm,标定后轨迹误差缩小到20μm以内,有效提高了并联平台的精度,验证了标定结果的有效性.The kinematic parameters of a 3-PRR planar parallel manipulator driven by linear ultrasonic motors are calibrated based on visual measurement technology. Firstly, the structure of the 3-PRR manipulator is introduced, and then the kinematic model of the manipulator and the error function are deduced. To realize kinematic calibration of parallel manipulator, charge coupled device （CCD） camera is adopted as the external measurement device. By using the technologies of image processing, the center of the artificial features fixed on the moving platform is located to realize accurate pose measurement of the moving platform. Finally, particle swarm optimization （PSO） algorithm is employed to optimize and calibrate the kinematic parameters of parallel manipulator. Calibration experiments show that the trajectory of the moving platform is an ellipse with 16 mm major axis and 10 mm minor axis, the maximum trajectory error is greater than 800μm before calibration, but the trajectory error is reduced to within 20 p.m after calibration. As a result, the accuracy of the parallel manipulator is greatly improved, and the proposed calibration approach is further proved to be effective.

关 键 词：并联平台 运动学标定 直线超声电机 视觉测量 

分 类 号：TP242[自动化与计算机技术—检测技术与自动化装置]